1. Field of the Invention
The field of the invention relates to wound healing and compositions and methods that are useful to treat wounds. More particularly, the field relates to compositions comprising cellulose hydrogel membranes that are useful to treat wounds, including ocular wounds.
2. Description of the Related Art
Wounds that do not heal readily can cause a subject considerable physical, emotional, and social distress as well as significant financial expense. In addition, wounds that are not properly treated shortly after injury have an increased incidence of complications and a longer recovery and sometimes do not heal properly. Wounds that fail to heal properly and become infected often require excision of the affected tissue.
The most commonly used treatment for wound healing involves the use of wound dressings. Wound dressings are typically occlusive and provide a moist environment to facilitate healing. Numerous types of wound dressings are now in use.
Ocular wounds are particularly challenging wounds to treat. Ocular injuries are common, especially in certain work environments, and have potential to cause significant morbidity and disability. Workers who have the highest risk of eye injuries include fabricators, laborers, equipment operators, repair workers, and production and precision workers. More than one half of work-related eye injuries occur in the manufacturing, service, and construction industries. Most chemical and thermal eye injuries occur when persons are at work. Injuries can range from mild damage to ocular surface from foreign material to severe penetrating trauma usually related to blast or projectile injury. Penetrating injuries often require primary surgical intervention to close the wounds and treatment or provision of prophylaxis against secondary ocular infection.
Ocular injury is also highly prevalent on the battlefield in combat situations. Despite the eye's seemingly insignificant size, accounting for only 0.1% of the body's frontal silhouette, the incidence of ocular injury in combat has been shown to be 20 to 50 times greater than expected by its surface area. Typical injuries include penetration from metallic fragments, corneal laceration, and corneal punctures.
In the military context, current mitigation techniques for ocular injuries focus on prevention through routine use of eye shields, which is not particularly successful. Treatment of injuries frequently requires donor tissue, which is not always readily available, especially in the theater of combat. Secondary repair and ocular reconstruction from battlefield injuries typically occurs at major military hospital settings. However, access to adequate ophthalmic facilities for primary repair of penetrating injuries varies tremendously with the location and context of the military environment.
Hydrogels are water-insoluble polymers having the ability to swell in water or aqueous solution without dissolution and to retain a significant portion of water or aqueous solution within its structure. Hydrogels can possess a degree of flexibility similar to natural tissue, due to their significant water content and hydrogels can have various applications. Attempts have been made to improve upon certain properties of hydrogels, for example, to increase strength, water content, transparency, permeability or biocompatibility properties, often with mixed results. For example, attempts have been made to optimize certain physical properties of hydrogels, such as strength, to suit various applications. However, such increases in strength often come at the expense of other properties of the hydrogel, such as transparency or water content.
A number of hydrogel compositions comprising synthetic or natural polymers have been discussed in the literature. There exists a need for improved compositions and methods comprising biocompatible hydrogel membranes to treat various types of wounds, for example, skin wounds, ocular abrasions and ocular surface damage caused by particulates and/or chemical exposure. There exists a further need for improved compositions and methods comprising biocompatible hydrogel membranes for tissue engineering applications, such as ocular reconstruction following complex injury.
This background information is provided for the purpose of making information believed by the applicant to be of possible relevance to the present invention. No admission is necessarily intended, nor should it be construed, that any of the preceding information constitutes prior art against the present invention.